i have to say the game got like million buttons and similar stuff

does it work with controllers say... xbox controller?

i'm not a very good PC gamer but i love classics and whatnot

Yes it does. For details check this thread:
http://www.gog.com/forum/thief_series/anyone_tried_using_a_gamepad_now_hear_me_out

"can I use a piece of barbed wire instead of a spoon to scoop peanut butter out of the jar?"

yes you can. but you should not.

Haha.

To be fair, in the thread that DeMignon linked, the OP makes some interesting arguments for why analog movement makes sense for the game. I would never want to play without mouselook, but it's true that the three movement speeds (modified to six based on whether Garrett is standing or crouching) can be a little awkward on keyboard.

I've been playing it with a 360 controller with great success. It took some fiddling with Xpadder (and the key bindings) to get it right, but it's been absolutely fine for me.